Prevalence and Diversity of Severe Fever with Thrombocytopenia Syndrome Virus and Co-Infection with Babesia microti in Ticks from Central and Eastern Parts of China.

This study was conducted to investigate tick species that may harbour severe fever with thrombocytopenia syndrome virus (SFTSV) and Babesia microti in the provinces of Henan, Anhui, and Zhejiang, as well as in Shanghai in the central and eastern parts of China. Between March and September 2023, 721 pools of ticks were collected belonging to three genera and five species: Haemaphysalis longicornis (n = 612; 84.9%), Haemaphysalis fusca (n = 94; 13.0%), Rhipicephalus microplus (n = 10; 1.4%), Amblyomma testudinarium (n = 3; 0.4%), and Haemaphysalis wellingtoni (n = 2; 0.3%). The SFTSV-positive pool rate was 20.0%, 13.0%, 5.8%, and 4.1% in Xinyang, Henan; Songjiang, Shanghai; Lu'an, Anhui; and Zhoushan, Zhejiang, respectively. SFTSV was detected in all five tick species collected. Among the SFTSV-positive pools, H. longicornis constituted the highest proportion (83.9%, 78/93), whereas pools containing R. microplus and H. wellingtoni each represented the lowest proportion (1.1%, 1/93). Babesia microti was assayed only in these SFTSV-positive tick pools, and co-infection was found in both H. longicornis and H. wellingtoni, though it was most frequent in H. longicornis.